~~ Methods for Function eulerian ~~

A generic function that returns an eulerian (or nearly eulerian) path based on self.

Usage

eulerian(self, start=NULL,weighted=TRUE)

Arguments

self: -- see below
start: -- see below
weighted: -- see below

Value

A vector representing the eulerian- a character vector of node names for a graph, otherwise a numeric vector. If the graph is not connected, the result is a list of eulerians for each connected component.

Methods

self = "even_graph": Uses etour to construct the eulerian. If weighted is TRUE a weighted eulerian is constructed, otherwise weights are ignored. A non-null start is the eulerian starting point.
self = "graphNEL": Augments the graph using mk_euler_graph, then invokes eulerian again on the augmented verion. If self is not connected, (approximate) eulerians are formed for each connected component, which are returned as a list.
self = "matrix": Builds a graph using mk_euler_graph, then invokes eulerian again on the result.
self = "numeric": Builds a graph with self nodes using mk_euler_graph, then invokes eulerian again on the result.
self = "ANY": Builds a graph using mk_euler_graph, then invokes eulerian again on the result.

References

C. Hierholzer (1873). Uber die Moglichkeit, einen Linienzug ohne Wiederholung und ohne Unterbrechung zu umfahren. Math. Annalen VI, pp. 30-32.

Also, see overview

Author

C.B. Hurley and R.W. Oldford

Examples


require(PairViz)

d <- as.matrix(eurodist)[1:8,1:8]   # pick the first 8 cities

eulerian(d)
#>  [1] 4 3 6 4 5 3 8 4 7 6 7 3 2 8 5 6 2 5 8 7 5 1 8 6 1 3 2 4 1 7 2 1
eulerian(d, weighted=FALSE) # In this case, starts at city 1 and ends at city 8
#>  [1] 1 2 3 1 4 2 5 1 6 2 7 1 8 2 3 4 5 3 6 4 7 3 8 4 5 6 7 5 8 6 7 8